Skip to main content
VulnerabilityPublished Updated

CVE-2026-31630: Linux kernel · rxrpc: proc: size address buffers for %pISpc output

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in db297c78ce537c9ac96f0eda9b25ad72c8caefa9 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in db297c78ce537c9ac96f0eda9b25ad72c8caefa9, a6042b8066b24dbcc7945616a157d4d43e463668, a44ce6aa2efb61fe44f2cfab72bb01544bbca272 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < db297c78ce537c9ac96f0eda9b25ad72c8caefa9
Fixed in
  • db297c78ce537c9ac96f0eda9b25ad72c8caefa9
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < a6042b8066b24dbcc7945616a157d4d43e463668
Fixed in
  • a6042b8066b24dbcc7945616a157d4d43e463668
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < a44ce6aa2efb61fe44f2cfab72bb01544bbca272
Fixed in
  • a44ce6aa2efb61fe44f2cfab72bb01544bbca272
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < 808a34cdbe8ce336c202d8ea6d5e48496764dc37
Fixed in
  • 808a34cdbe8ce336c202d8ea6d5e48496764dc37
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < 625af53a1564e31bb2df9adc3739df46137f46c1
Fixed in
  • 625af53a1564e31bb2df9adc3739df46137f46c1
LinuxLinuxAffected
  • ≥ 75b54cb57ca34cbe7a87c6ac757c55360a624590, < 386c86412608d3449006a318a662cbcd6ca1f668
Fixed in
  • 386c86412608d3449006a318a662cbcd6ca1f668

Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: proc: size address buffers for %pISpc output The AF_RXRPC procfs helpers format local and remote socket addresses into fixed 50-byte stack buffers with "%pISpc". That is too small for the longest current-tree IPv6-with-port form the formatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a dotted-quad tail not only for v4mapped addresses, but also for ISATAP addresses via ipv6_addr_is_isatap(). As a result, a case such as [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535 is possible with the current formatter. That is 50 visible characters, so 51 bytes including the trailing NUL, which does not fit in the existing char[50] buffers used by net/rxrpc/proc.c. Size the buffers from the formatter's maximum textual form and switch the call sites to scnprintf(). Changes since v1: - correct the changelog to cite the actual maximum current-tree case explicitly - frame the proof around the ISATAP formatting path instead of the earlier mapped-v4 example

References

Community reviews

Loading reviews…